Internal language selector

Instead of relying on the device language, add ability to set the
language in the app.

app/build.gradle

@@ -88,6 +88,9 @@ android {
         viewBinding true
         buildConfig true
     }
+    androidResources {
+        generateLocaleConfig true
+    }
     lint {
         abortOnError false
         checkReleaseBuilds false

app/src/main/AndroidManifest.xml

@@ -189,6 +189,14 @@
         <meta-data
             android:name="com.samsung.android.multidisplay.keep_process_alive"
             android:value="true" />
+        <service
+            android:name="androidx.appcompat.app.AppLocalesMetadataHolderService"
+            android:enabled="false"
+            android:exported="false">
+            <meta-data
+                android:name="autoStoreLocales"
+                android:value="true" />
+        </service>
     </application>
 
 </manifest>

app/src/main/java/free/rm/skytube/gui/fragments/preferences/VideoPlayerPreferenceFragment.java

@@ -18,13 +18,26 @@
 package free.rm.skytube.gui.fragments.preferences;
 
 import android.content.SharedPreferences;
+import android.content.res.XmlResourceParser;
 import android.os.Bundle;
 
+import androidx.appcompat.app.AppCompatDelegate;
+import androidx.core.os.LocaleListCompat;
 import androidx.preference.ListPreference;
 import androidx.preference.Preference;
 import androidx.preference.PreferenceFragmentCompat;
 
+import com.google.common.base.Joiner;
+
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+
+import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
 
 import free.rm.skytube.BuildConfig;
 import free.rm.skytube.R;
@@ -44,7 +57,7 @@ public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
 		// if we are running an OSS version, then remove the last option (i.e. the "official" player
 		// option)
 		if (BuildConfig.FLAVOR.equals("oss")) {
-			final ListPreference    videoPlayersListPref = (ListPreference) getPreferenceManager().findPreference(getString(R.string.pref_key_choose_player));
+			final ListPreference    videoPlayersListPref = getPreferenceManager().findPreference(getString(R.string.pref_key_choose_player));
 			final CharSequence[]    videoPlayersList = videoPlayersListPref.getEntries();
 			CharSequence[]          modifiedVideoPlayersList = Arrays.copyOf(videoPlayersList, videoPlayersList.length - 1);
 
@@ -58,6 +71,43 @@ public void onCreatePreferences(Bundle savedInstanceState, String rootKey) {
 		});
 
 		configureCountrySelector();
+		configureLanguageSelector();
+	}
+
+	private List<String> getLanguages() {
+		List<String> result = new ArrayList<>();
+		try {
+			XmlResourceParser xpp = getResources().getXml(R.xml._generated_res_locale_config);
+			while (xpp.getEventType() != XmlPullParser.END_DOCUMENT) {
+				if (xpp.getEventType() == XmlPullParser.START_TAG) {
+					if ("locale".equals(xpp.getName()) && xpp.getAttributeCount() > 0 && "name".equals(xpp.getAttributeName(0))) {
+						result.add(xpp.getAttributeValue(0));
+					}
+				}
+				xpp.next();
+			}
+			Logger.i(this, "Language list:"+result);
+		} catch(XmlPullParserException|IOException e) {
+			Logger.e(this, "Unable to parse locale config: "+e.getMessage(), e);
+		}
+		return result;
+	}
+
+	private void configureLanguageSelector() {
+		ListPreference languageSelector = findPreference(getString(R.string.pref_key_app_language));
+
+		List<String> languages = getLanguages();
+		LocaleListCompat localeList = LocaleListCompat.forLanguageTags(Joiner.on(",").join(languages));
+		int size = localeList.size();
+		String[] localeCodes = new String[size];
+		String[] localeNames = new String[size];
+		for (int i = 0;i<size;i++) {
+			Locale locale = localeList.get(i);
+			localeNames[i] = locale.getDisplayName();
+			localeCodes[i] = locale.getLanguage();
+		}
+		languageSelector.setEntries(localeNames);
+		languageSelector.setEntryValues(localeCodes);
 	}
 
 	private void configureCountrySelector() {
@@ -79,5 +129,10 @@ public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, Strin
 			NewPipeService.setCountry(newCountry);
 			EventBus.getInstance().notifyMainTabChanged(EventBus.SettingChange.CONTENT_COUNTRY);
 		}
+		if (getString(R.string.pref_key_app_language).equals(key)) {
+			String newLanguage = sharedPreferences.getString(key, null);
+			LocaleListCompat appLocale = LocaleListCompat.forLanguageTags(newLanguage);
+			AppCompatDelegate.setApplicationLocales(appLocale);
+		}
 	}
 }

app/src/main/res/resources.properties

@@ -0,0 +1 @@
+unqualifiedResLocale=en

app/src/main/res/values/strings_preferences.xml

@@ -746,6 +746,11 @@
     <string name="pref_key_default_content_country" translatable="false">pref_key_default_content_country</string>
     <string name="pref_title_default_content_country">Default content country</string>
     <string name="pref_summary_default_content_country">Show content intended for this country: %s</string>
+
+    <string name="pref_key_app_language" translatable="false">pref_key_app_language</string>
+    <string name="pref_title_app_language">Application Language</string>
+    <string name="pref_summary_app_language">The language used for all the labels in the application</string>
+
     <!--
         SPONSORBLOCK
     -->

app/src/main/res/xml/preference_video_player.xml

@@ -64,6 +64,12 @@
 		app:entryValues="@array/country_codes"
 		app:defaultValue=""
 		app:iconSpaceReserved="false" />
+	<ListPreference
+		app:key="@string/pref_key_app_language"
+		app:title="@string/pref_title_app_language"
+		app:summary="@string/pref_summary_app_language"
+		app:defaultValue=""
+		app:iconSpaceReserved="false"/>
 
 	<CheckBoxPreference
 		app:key="@string/pref_key_use_newer_formats"